Picked up a third head. This is a single-ended class-A champ kit somebody else already assembled. Price is right as long as the tubes are still good. Looks like about 5 watts. I think it's only got a volume control. 2 audio signal tubes and a tube rectifier.

There are some champ kits with parallel single-ended class-A outputs, which look really interesting.

This should be fun. I'll have to decide on a speaker and make a cabinet. This project might sit on a shelf for a while, or I might run it as-is.

I've got a single ended project in mind also, and I'm planning to use a 12" speaker to for a few reasons, mainly to allow for more options as 12's are the most popular size. Also I don't want to sacrifice bass, even though it will be a relatively low power single ended amp. I would recommend a 10" or 12" speaker instead of the typical 8" found in the Champ-Amp.

It arrived yesterday intact, packed as a chassis in a box with tubes sticking out the top of the chassis! The whole thing is so light! I hope to try it tonight. I will be listening for low hum and hiss.

I was surprised the filament wires are not twisted. Inside it looks surprisingly random.